Scientists Recommend 4,000 IU – 8,000 IU of Vitamin D Per Day

There is now wide scientific support¹ for maintaining blood levels of vitamin D between 40 ng/ml – 80 ng/ml, with 60 ng/ml – 80 ng/ml now the gold standard range for cancer prevention.  Surprisingly the researchers found that a supplemental dose of 9,600 IU of vitamin D per day enabled 97% of participants to reach 40 ng/ml – the bottom end of the protective range.

“We found that daily intakes of vitamin D by adults in the range of 4000-8000 IU are needed to maintain blood levels of vitamin D metabolites in the range needed to reduce by about half the risk of several diseases—breast cancer, colon cancer, multiple sclerosis, and type 1 diabetes,” said Cedric Garland, DrPH, professor of family and preventive medicine at UC San Diego Moores Cancer Center. “I was surprised to find that the intakes required to maintain vitamin D status for disease prevention were so high—much higher than the minimal intake of vitamin D of 400 IU/day that was needed to defeat rickets in the 20th century.”

Interest in larger doses was spurred in December of last year, when a National Academy of Sciences Institute of Medicine committee identified 4000 IU/day of vitamin D as safe for every day use by adults and children nine years and older, with intakes in the range of 1000-3000 IU/day for infants and children through age eight years old.
20-30 minutes of sun exposure produces 10,000 IU of vitamin D.  In the current study no patient talking 10,000 IU of vitamin D daily came close to the vitamin D toxicity level of 200 ng/ml. 

It is quite clear that when vitamin D levels are not maintained in a more optimal range than existing health problems can worsen. It is also now clear that significantly higher vitamin D intake may be required to keep vitamin D in a health-protective range.